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L. S. GRAVES.

BLBVATOR SAPETY DEVICE. No. 319,480. Patented June 9, 1885.

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LORENZO' S. GRAVES, OF ROCHESTER, NEW YORK, ASSIGNOR TO` LORENZO S.GRAVES 8L SON, OF SAME PLAGE.

ELEVATOR `SAFETY DEVICE.

SPECIFICATION forming part of Letters Patent No. 319,480, dated June 9,1885.

Application filed January 30, 1885.

To all whom it may cof/werfe.-

Be it known that I, LORENZO S. GaAvns, of Rochester, New York, haveinvented an Improved Elevator Safety Device, of which the following is aspecification, reference being had to the accompanying drawings.

My invention relates to au improved elevator safety device, which isfully described in the following specification, and the novel featuresthereof specified in the annexed claims.

My improved elevator safety device is represented in the accompanyingdrawings, in which Figure 1 is a side elevation of the upper portion ofan elevator-car embodying my improvement. Fig. 2 is a plan view ofthesame. Fig. 3 represents the sheave-pulley and clamping device. Fig. 4tis a section through the sheave-pulley and clamps on the line xx, Fig.2. Fig. 5 is a section through the sheave-pulley on the line y y, Fig.4, showing the manner of attaching the ropes thereto.

In the accompanying` drawings, representing my present invention, A isthe elevatorcar, B B,the guideways; OO,the cross-beams, to which the caris attached; D D', the main lifting-cables; E E', the cables connectedwith the counterbalance-weight; F F, the sheavepulleys, and G G theclamping-screws. The elevator-car may be of any ordinary or preferredconstruction, and ornamented, if designed for use in the conveyance ofpassengers. The main lifting-cables D D areconnected with any suitablemechanism for raising and lowering the car, constructed and arranged inany ordinary or preferred manner for this purpose. Thecounterbalance-cables E E extend upward from the car and pass oversuitablepulleys, and thence downward to a counterbalancing weight,H,arranged to travel 'up and down in a suitable well alongside of theelevator, or in any other suitable relation therewith. Both the mainlifting-cables D D and the cables E E connected with the counterbalancepass around the pulleys o o o 0,and extend laterally to thesheave-pulleys F F, which are fastened to the screws G G', thearrangement being such that in case the main lifting-cables break orbecome slack from any 5o cause the counterbalance weight, acting throughthe cables E E', will cause the sheaves (No model.)

F F and the screws G G to revolve, thereby drawing the ends o o of thecross-beams O O together, as indicated by the dotted lines in Fig. 3,and clamping them firmly against the 5 5 opposite sides of the guidewaysB B, arresting the descent of the car without jar or jerk, andpreventingaccidents from the breaking or slacking of the mainlifting-cables. The ends of the counterbalance-cables are wound one 6cor more times about the sheaves F F', and the two sets of cables areattached t0 opposite sides of the sheaves, so that the strain or pull ofone set of cables tends to cause the sheaves to revolve in onedirection, while the strain of the other set tends to turn the sheavesin the opposite direction. The screws G G', the opposite ends of whichare'preferably provided with threads cut in opposite directions, asindicated in Fig. 3, may be threaded directly into 7o the cross-beams,or they may be inserted into the nuts?1 r', fastened to thecross-beams,thelatter arrangement facilitating the setting up of theapparatus. It is obvious, however, that one end only of the screws needbe threaded, the other end being provided with a collar outside of oneof the cross-beams, to resist the strain caused by clamping the ends ofthese crossbeams against the guideways. In either case the lead of thescrew should be in such a direc- 8o tion that the turning of the sheavesby the strain of the counterbalance-cables attached thereto will drawthe ends of the cross-beams together, or move one end of one of thecrossbeams toward the corresponding end of the other. The pulleys o oo 0are mounted so as to revolve independently of each other on suitablebolts or studs inserted in the crossbearns.

As indicated in the drawings, the main lift- 9e ing cables D D passfrom. the corner pulleys to the lower sides ofthe sheaves F F, while thecounterbalance-cables pass to the upper sides4 of the sheaves, in orderthat the strain or pull of the two sets of cables may give the sheaves atendency to revolve in opposite directions, and so that in case thestrain of the lifting-cables is released or slackened thecounterweightcables may turn the sheaves and screws, thereby clampingthe ends ofthe cross-beams against roo the guideways. rlhe ends of thecables are fastened, to the sheaves, as represented in any otherpreferred manner. lThe clampingbeams may, if desired, beplaced below thecar, .the cables being led around suitable pulleys, so as to leavetheinterior of the car unobstructed.

In the drawings I have represented the clamps c c as formed by the endsof the crossbeams O C', but it is obvious that the clamps may beindependent of the cross beam or beams, if preferred, being hinged orotherwise secured thereto so that their outer ends are capable of beingmoved to and from the guideways. .The car may be guided by thecrossbeams alone, the clamp e @being so conthe guideways, but I preferto apply to the car the additional guides, (represented as J J, Fig. 1,)which may be made adjustable either in whole or in part to and from theguideways. The lower part of the car is provided with guides arranged inany ordinary or preferred manner.

In order to, secure equality of strain on the counterbalancecables, theymay be caused to pass around a pulley attached to the counterbalance; orthey may be fastened to the ends of a compensating-lever pivoted at itsmiddle to the weight.

The operation of my improved 'safety device for elevators will have beenalready understood from the foregoing description. The weight of the caron the main lifting-cables holds the sheaves F F' with one or more turnsrstrain on them is released from any cause, the

counterbalan ce-weight, through its cables, will cause the sheaves torevolve, thereby, by .means of the screws G G', drawing the clamps v etogether against the guideways, and causing sufficient friction toprevent the descent of the car. The movement of the ear is arrested in agradual manner and without jerk or strain, such as is produced by thesafety devices now generally employed on elevators.

`balance-cables, substantially as described.

2. The combination, with the elevator-car A and guideways B B', of thecross-beams C C', screws G G', and clamps o fv, substantially asdescribed.A

3. The combination, with the elevator-car A, guideways B B',screw-clamps e o, lifting' cable D, counterbalancc-cable E, and suitablecorner pulley or pulleys, o, substantially as described.

4. The combination, with the car A, of the cross-beams C C', clamps fuo, screw G, and nut r, substantially as described.

5. rlhe combination, with the car A and guideways B B', of thecross-beams C C', screws G G', sheaves F F', corner pulleys, o o', andthe lifting-cables and counterbalance-cables, substantially asdescribed.

6. The herein described safety attachment.'

for elevators, consisting, essentially, of a friction clamp attached tothe car and engaging the guideways, in combination with actuatingsheaves, and the lifting and counterbalance cables, the latter appliedto the actuating-sheaves and wound in opposite directions thereon,substantially as described.

7. In combination, with an elevator-car and its guides, a friction-clamp attached to the car, a screw for actuating said clamps, a sheave orpulley for rotating said screw, and a liftingcable andcounterbalancecable applied to said sheave or pulley and acting thereonin opposition to each other to hold the screw stationary, whereby theclamp is held suspended by opposing strains upon thc lifting andcounterbalance cables, and is applied by the counterbalance when thestrain is relaxed upon the lifting-cable, substantially as described.

LORENZO S. GRAVES.

Witnesses:

GEO. B. SELDEN. L. A. KANE.

ICO

